Part II - Lectures 8 & 9.doc

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School

University of British Columbia

Department

Psychology

Course

PSYC 260

Professor

Julia Kam

Semester

Spring

Description

Attention
Consciousness
- Operational definition: when one reports (the feeling and content of) awareness of a
stimulus
o Cannot apply to animals and infants, who cannot express what they are
feeling/thinking
o Brain death is characterized by the loss of consciousness
- A very subjective experience and cannot be observed by others
- How do we study it?
o Unmasked condition vs. masked condition
o Stimulus in the masked condition is shown for an extremely short amount of time
o We infer from brain activity that a stimulus was consciously experienced
o Results show that stimuli which we are not consciously aware of produce weaker
and less wide-spread activity in the brain
- Researchers suggest that our consciousness experience only takes up about 5% to 10%
of our brain activity—the rest is subconscious experience
o “Unconscious” experience is not used as the word implies the loss of
consciousness
Attention
- “[Attention] is the taking possession of the mind in clear and vivid form, of one out of
what seem several simultaneously possible objects or trains of thoughts. It implies
withdrawal from some things in order to deal effectively with others.” – William James
o Note that it is not only stimuli in the external environment that can catch our
attention. It can also be our own thoughts and memories.
- Our senses are bombarded with stimuli. Yet, our ability to process all this information at
once is limited.
- If you don’t attend to it, you don’t see it.
- “Attention” encompasses the various ways by which we select among all there is to be
looked at, listened to, felt, smelled, or tasted. - Sensory input  sensory processing  attention & memory (perception  decision
making  response selection)  motor output
Purposes of conscious attention
- Monitoring our interactions with the environment
- Linking our past (memories) and our present (sensations) to give us a sense of
continuity of experience
- Controlling and planning for our future actions
Inattentional blindness
- Failure to notice the existence of an unexpected item
- The inability to perceive something that is within one’s direct perceptual field because
one is attending to something else
- Attention to one thing causes us to miss what to others may seem to be obvious
Change blindness
- The failure to notice an obvious change
Unilateral spatial neglect
- Neurological condition wherein individuals show a tendency to ignore (all forms of
sensory stimuli on) one side of the body or objects
- The main issue is usually a loss of attention, as opposed to impaired sensory perception
- The mental image created in the head is also affected.
o Peggy: when asked to draw daisies from memory/imagery, she only draws the
right side.
- Almost always happen to people with damage to right hemisphere of the brain, meaning
that they neglect the left side
- The right hemisphere tends to attend to both the left and right visual fields, whereas the
left hemisphere only attends to the right visual field. Therefore, when the left hemisphere
is damaged, the right hemisphere can still attend to the right visual space; in contrast,
damage to the right hemisphere leaves the left visual space unattended.
- Parietal lobe is responsible for creating a 3D representation of the world, so damage to
either side can cause unilateral spatial neglect.
- Several strategies to increase attention to neglect side: o Reminder to pay attention to the unattended side
o Look to the neglected side
o Arm crossing
Controlled vs. automatic attention
- Controlled attention (A.K.A. voluntary attention): conscious and willful decision to
attend to specific aspect of visual environment
o Requires intentional efforts
o Requires conscious awareness
o The amount of attention and efforts required decreases with practice
o Top-down attention
- Automatic attention (A.K.A. reflexive attention): automatic tendency of our attention to
get drawn to “eye-catching” stimuli
o Requires little or no intention/effort
o Generally outside of consciousness awareness
o Bottom-up attention
- There is always an interplay between controlled attention and automatic attention
Bottom-up attention
- What are the effects of “eye-catching” stimuli in the environment?
- Subjects who take a walk in the nature are exposed to calming and moderately eye-
catching stimuli
- Subjects who take a walk in the urban city are constantly exposed to very eye-catching
stimuli
- Stimuli in urban environment worsened attentional task performance, which was
identifying the direction of a particular arrow among a number of irrelevant arrows
o Individuals who went for a walk in the nature were less distracted by the
irrelevant stimuli, whereas the individuals who walked in the urban city were less
able to suppress the surrounding stimuli.
Top-down attention
- Previous knowledge and experience dictate what we represent/perceive of a stimulus Role of experience in visual attention
1. Does video-game playing increase attentional capacity?
a. Flanker compatibility task
 Subjects are actually less distracted by the distractor in a difficult
condition due to the large amount of attention required to focus on the
target
 Large distractor effect in easy conditions and small distractor effect in
difficult conditions
 Video game players showed enhanced attentional capacity, as difficulty
level of the task does not affect their level of performance (measured by
reaction time)
b. Enumeration task
 A screen is flashed very briefly and subjects must determine how many
squared there are.
 Video game players showed more accurate performance
2. Does video-game playing facilitate processing outside the training range?
o Participants were supposed to find a target among distractors
o Get a measure of the spatial allocation of attention
o Video game players showed enhanced allocation of spatial attention (the ability
to focus on specific stimuli in a visual environment)
- Taken together, action-video-game players displayed superior task performance in
different aspects of visual attention compared to non-video-game players
o Video game players showed superior performance in spatial attention and
attentional capacity!
Friesen et al., 2004
- Does attention to gaze direction represent a different type of reflexive orienting?
- Does orienting to other people’s gaze direction represent reflexive attentional orienting?
o Similarity of gaze direction to other types of reflexive orienting  Observed with non-predictive stimulus: we are faster at detecting targets
of other people’s gaze even if we are told that the stimuli are not in that
direction